The invention relates to a housing for electronic devices, having a base that comprises profiled metal bars that have at least one longitudinal chamber, having at least one metal covering part that is secured to the base and has an inwardly-chamfered edge strip, and having at least one contact spring that has a U-shaped cross-section between the metal bars and the covering part.
One particular application of the invention is in housings as well as device cabinets for industrial electronics whose componentry is sensitive to high-frequency interfering radiation and requires extensive shielding.
To serve as an HF shield, the base and covering parts must be electrically well-connected everywhere. The measures necessary for assuring this require large amounts of resources and are expensive. They involve the creation of contact zones located opposite one another and between which contact springs or spring strips are inserted that produce the desired electrical contact between the edges of the covering parts and the metal bars of the base. The metal bars of the housing, which serve as supporting and connecting components, are extruded hollow profiles whose particularly shaped cross-section, for reasons of stability and as a weight- and material-saving measure, has one or a plurality of channel-like, longitudinal chambers (German Patent DE-PS 4,127,468) on the inside that extend in the longitudinal direction. Before a surface protector, that is, a lacquer, is applied by means of normal lacquer spraying, electrostatic powder coating or also by means of wet or dry spray application, the required contact zones must remain free from lacquer. To achieve this, up to now adhesive strips provided on one side with pressure adhesive have been applied to the metal bars and must be removed after lacquering. Because this procedure is only performed in manual labor, it is associated with considerable costs, and a particular disadvantage of this procedure is that small and barely noticeable traces of the glue remain on the contact zones, preventing the production of an electrical contact at these locations and thus interrupting the shield.
Contact springs are known (German Patent 4,110,800) that have a U-cross-section for producing a seal against high frequencies of the longitudinal gaps between the front plates of components of electronic devices that can be inserted into HF-proof housings. These contact springs are inserted into longitudinal ribs that freely project laterally from the back side of the front plates; of course, a prerequisite is that the metal ribs remain bare.